In electrical impedance tomography, one tries to recover the spatial conductivity
distribution inside a body from boundary measurements of current and voltage.
In many practically important situations, the object has known background
conductivity but it is contaminated by inhomogeneities.
The factorization method of Andreas Kirsch provides a tool for locating
such inclusions. In earlier work, it has been shown, both theoretically and
numerically, that the inhomogeneities can be characterized by the factorization technique
if the input current can be controlled and the potential can be measured everywhere on
the object boundary. However, in real-world electrode applications, one can only
control the net currents through certain surface patches and measure the
corresponding potentials on the electrodes. In this work,
the factorization method is translated to the framework of the complete electrode model
of electrical impedance tomography and its functionality is demonstrated through two-dimensional
numerical experiments. Special attention is paid to the efficient implementation of the
algorithm in polygonal domains.